Traditionally, in the signing industry, particularly in connection with large illuminated signs as may be used in advertising or in appending large, illuminated labels to buildings, channel letters and light boxes have become standards. Typically, they have been illuminated internally with neon and fluorescent tubes, incandescent lamps, and more recently with light emitting diode (LED) technology. All of these technologies require the use of transformers, driver electronics, and electrical contacts to be located in the channel letter or light box “can”, or holding structure, which may normally have metal sides and a translucent plastic face. In many instances, channel letter signs and light boxes are located in places that are not easy to access, for example, at the top of a multi-story building. Thus, replacing serviceable parts and repairing malfunctioning components can be time-consuming, costly in terms of labor and equipment, and potentially dangerous. A compelling need has thus been recognized in connection with illuminating channel letter signage and light boxes in a manner to permit serviceable components to be located in locations that are easy to access.
Fiber optic technology has provided many advantages in a variety of contexts and has been contemplated previously in connection with lighting applications. End-lit fibers emit light at terminal ends of fibers while very little light typically is emitted through the cylindrical fiber walls. U.S. Pat. No. 6,024,476 relates to the use of “end-lit” fibers in lighting. There, bunches of end-lit fibers are grouped together to create an aggregately much greater light output than is possible with a single end-lit fiber. Apart from the intricacies encountered in connection with bunching the fibers together, they are prone to easy breakage when bunched and difficult to maintain or replace. Moreover, retrofitting an existing channel letter in the manner taught by this patent would be impractical.
“Side-lit” fibers, in contrast, emit light isotropically through the cylindrical walls of a fiber, that is, outwardly along an infinite number of radial directions as defined with respect to a central longitudinal axis of the fiber. U.S. Pat. No. 6,123,442 describes the use of side-lit fibers in lighting. However, it has been found that the light provided by such fibers is often inconsistent and unpredictable, especially when intricate configurations (e.g. of letters or numerals) are contemplated. Also, maintenance is difficult and costly in that entire lengths of fiber often need to be replaced even in the case of minor performance issues. Moreover, since side lit fiber is designed to lose or emit light along its length, as the distance between the light engine and the channel letter is increased, the useable light in the can is proportionally diminished.
In view of the foregoing, a general need has been recognized in connection with providing a cost-effective lighting arrangement that employs versatile technology such as fiber optics but improves upon the shortcomings hitherto encountered with such technology.